It seems like meson is dropping rust_args when testing the rust compiler, so we just append them directly to rustc
BUILD STYLES ============ These shell snippets provide support for multiple build systems, i.e GNU configure, CMake, etc. A build style file must provide at least the following functions: - do_configure - do_build - do_install If a source package defines its own do_xxx() function, the function defined in the build style file is simply ignored.